Memory leak when use AFHTTPSessionManager

Question

Env:

1. iOS 13/iOS 10
2. Xcode 11.1
3. AFNetworking version: 3.2.1
4. Swift 4.2

Description: When use AFNetworking to post or get Json data, it will cause memory leak, I create a AFHTTPSessionManager like this:

private static func ConfigureAFManager(requestSerialization: HttpSerializationType = HttpSerializationType.HTTP,
                                           responseSerialization: HttpSerializationType = HttpSerializationType.JSON,
                                           timeout: TimeInterval = 30,
                                           headers: [String: String]? = nil
                                           ) -> AFHTTPSessionManager {
        let AFManager = AFHTTPSessionManager()
        if requestSerialization == .JSON {
            AFManager.requestSerializer = AFHTTPRequestSerializer()
        }
        if responseSerialization == .HTTP {
            AFManager.responseSerializer = AFHTTPResponseSerializer()
        }
        for (key, value) in headers ?? [:] {
            AFManager.requestSerializer.setValue(value, forHTTPHeaderField: key)
        }

        AFManager.requestSerializer.timeoutInterval = timeout;
        return AFManager
    }

then I use it to perform post action:

static func POST(httpURL: String,
                     parameter: Any?,
                     timeout: TimeInterval = 30,
                     headers: [String: String]? = nil,
                     requestSerialization: HttpSerializationType = HttpSerializationType.HTTP,
                     responseSerialization: HttpSerializationType = HttpSerializationType.JSON,
                     success: ((Any?) -> Void)?,
                     fail: ((Error?) -> Void)?) -> Void
    {
        let AFManager = self.ConfigureAFManager(requestSerialization: requestSerialization, responseSerialization: responseSerialization, timeout: timeout, headers: headers)
        AFManager.post(httpURL, parameters: parameter, progress: nil, success: { (task, response) in
            success?(response)
        }) { (task, error) in
            fail?(error)
        }
    }

When I clicked the Debug Memory Graph on Xcode, I found that, there are some cycle reference between AFHTTPSessionManager and __NSURLSessionLocal.

Cycle reference Is this happening only in the 3.2.1 version of AFNetworking?

Answer 1

I know why, because AFNetWorking use URLSession it's delegate will establish a strong reference, so after use the AFHttpSessionManager should call invalidateSessionCancelingTasks